基于NETD的红外探测系统作用距离分析

Analysis of Operating Range of Infrared Detection System Based on NETD

由于红外焦平面阵列(Infrared Focal Plane Array,IRFPA)已成为红外探测器发展的主流,用IRFPA的参数来评价红外探测系统的综合性能变得至关重要。推导了以噪声等效温差(Noise Equivalent Temperature Difference,NETD)参数表示的红外探测系统的作用距离方程,考虑了背景辐射和目标成像弥散效应对探测的影响,计算了不同能见度条件下系统对点源目标的作用距离。结果表明,大气能见度越好,红外探测系统的作用距离就越远。分析了红外探测系统的探测能力随NETD值的变化.随着NETD值的增大,红外探测系统对目标的作用距离显著减小。研究结果能为红外探测系统的设计和性能指标评价提供参考。

Since Infrared Focal Plane Arrays （IRFPA） have become the main stream in the development of infrared detectors, the use of IRFPA parameters to evaluate the comprehensive performance of an infrared detection system is very important. The operating range equation of an infrared detection system represented by Noise Equivalent Temperature Difference （NETD） is deduced. Considering the influence of background radiation and target imaging dispersion effect on detection, the operating range of a system for a point target under different visibility conditions is calculated. The result shows that the better the visibility is, the farther the operating range of the infrared detection system is. The variation of the detecting capability of the infrared detection system with NETD is analyzed. With the increase of NETD, the operating range of the infrared detection system for the target decreases remarkably. The research result is of referential value to the design and performance index evaluation of infrared detection systems.